Liquid crystal display device

ABSTRACT

Discussed is a liquid crystal display device according to an embodiment including a substrate including a unit pixel having first to third sub-pixels arranged in a delta structure; and a first electrode and a second electrode in each of the first to third sub-pixels, each of the first and second electrodes including a first bar and a plurality of second bars branching off from the first bar, the first bar of the first electrode and the first bar of the second electrode facing each other and being parallel with each other, the second bars of the first electrode and the second bars of the second electrode interleaved with each other, wherein the first and second bars of the third sub-pixel makes first and second angles, respectively, relative to a first polarization axis.

CROSSS REFERENCE TO THE RELATED APPLICATIONS

The present application claims the priority benefit of the Korean PatentApplication No. 10-2015-0169515 filed in Republic of Korea on Nov. 30,2015, which is hereby incorporated by reference in its entirety for allpurposes as if fully set forth herein.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a liquid crystal display device (LCD).In particular, the present invention relates to an LCD including a nanocapsule liquid crystal layer.

Discussion of the Related Art

With the advancement of information society, the display field ofdisplaying electric information signals has been rapidly advanced.Accordingly, as flat display devices having advantages of thin profile,light weight and low power consumption, including a liquid crystaldisplay device (LCD), a plasma display panel device (PDP), anelectroluminescent display device (ELD), a field emission display device(FED) and the like have been introduced and have rapidly replaced aconventional cathode ray tube (CRT). Among the flat display devices,LCDs are most widely used in the fields of a laptop, monitor, television(TV) because they are excellent in displaying moving images and a highcontrast ratio.

FIG. 1 is a cross-sectional view illustrating an LCD according to arelated art. Referring to FIG. 1, the related art LCD 10 includes aliquid crystal panel having a first substrate 2 and a second substrate 4attached to each other with a liquid crystal layer 50 therebetween, anda backlight 60.

In detail, a thin film transistor Tr on the first substrate 2 includes agate electrode 12, a gate insulating layer 13, an active layer 14, ohmiccontact layers 15 a and 15 b, and source and drain electrodes 16 and 17,and is connected to a first electrode 19 in a pixel region P through acontact hole formed in an inter-layered insulating film 18. Further, ablack matrix 32 is below the second substrate 4, and has a lattice shapeto surround the pixel region P such that the black matrix 32 shields anon-display element such as the thin film transistor Tr and exposes thefirst electrode 19. Further, a color filter 34 is arranged in thelattice-shaped black matrix 32 corresponding to the pixel region P, anda second electrode is arranged to cover the black matrix 32 and thecolor filter 34.

Polarizing plates 20 and 30 each selectively transmitting apredetermined polarized light are attached below the first substrate 2and on the second substrate 4, respectively. Further, a first alignmentlayer 31 a having a surface rubbed in a predetermined direction isbetween the liquid crystal layer 50 and the first electrode 19, and asecond alignment layer 31 b having a surface rubbed in a predetermineddirection is between the liquid crystal layer 50 and the secondelectrode 36, and thus initial arrangement state and alignment directionof liquid crystal molecules are uniform. Further, to prevent a leakageof the liquid crystal layer 50, a seal pattern 70 is arranged along edgeportions of the first and second substrates 2 and 4. Since the LCD 10 isnot self-luminescent, the backlight 60 as a light source is arrangedbelow the liquid crystal panel to supply light to the liquid crystalpanel.

As the liquid crystal layer for the LCD 10, a nematic liquid crystal, asmetic liquid crystal, a cholesteric liquid crystal or the like is used,and the nematic liquid crystal is mostly used. However, in the relatedart LCD 10, there is an disadvantage that an alignment process whenattaching the two substrates 2 and 4 is additionally required after thesubstrates 2 and 4 are individually manufactured. Further, processes ofprinting and rubbing the alignment layers 31 a and 31 b to align theliquid crystal are required, and due to this processes, production rateis reduced. Further, a gap between the two substrates 2 and 4 needs tobe maintained after attaching the substrates 2 and 4 and injecting theliquid crystal between the substrates 2 and 4, and if a gap between thetwo substrates changes by an external pressure or impact, displayquality may be degraded.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to an LCD thatsubstantially obviates one or more of the problems due to limitationsand disadvantages of the related art. An object of the present inventionis to provide an LCD that can prevent a phenomenon of a non-uniformcolor coordinate.

Additional features and advantages of the disclosure will be set forthin the description which follows, and in part will be apparent from thedescription, or may be learned by practice of the disclosure. Theadvantages of the disclosure will be realized and attained by thestructure particularly pointed out in the written description and claimsas well as the appended drawings.

To achieve these and other advantages, and in accordance with thepurpose of the present invention, as embodied and broadly describedherein, a liquid crystal display device includes a substrate including aunit pixel having first to third sub-pixels arranged in a deltastructure; and a first electrode and a second electrode in each of thefirst to third sub-pixels, each of the first and second electrodesincluding a first bar and a plurality of second bars branching off fromthe first bar, the first bar of the first electrode and the first bar ofthe second electrode facing each other and being parallel with eachother, the second bars of the first electrode and the second bars of thesecond electrode interleaved with each other, wherein the first andsecond bars of the third sub-pixel makes first and second angles,respectively, relative to a first polarization axis.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the disclosure and are incorporated in and constitute apart of this specification, illustrate embodiments of the disclosure andtogether with the description serve to explain the principles of thedisclosure. In the drawings:

FIG. 1 is a cross-sectional view illustrating an LCD according to therelated art;

FIG. 2 is a cross-sectional view illustrating an LCD according to anembodiment of the present invention;

FIG. 3 is a view illustrating unit pixels of an LCD according to theembodiment of the present invention;

FIGS. 4A and 4B are views illustrating electrode arrangement structuresof sub-pixels of a unit pixel of FIG. 3;

FIG. 5 is a view illustrating a pixel arrangement produced with aplurality of unit pixels according to the embodiment of the presentinvention;

FIG. 6 is a view schematically illustrating the second sub-pixel ofFIGS. 4A and 4B;

FIG. 7 is a graph illustrating a relative light transmittance to arelative voltage applied to each sub-pixel of the embodiment of thepresent invention; and

FIG. 8 is a view illustrating brightness by area of each sub-pixelaccording to the embodiment of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to embodiments, examples of whichare illustrated in the accompanying drawings. The same or like referencenumbers may be used throughout the drawings to refer to the same or likeparts.

FIG. 2 is a cross-sectional view illustrating an LCD 100 according to anembodiment of the present invention. Referring to FIG. 2, the LCD 100 ofthe embodiment includes a substrate 101, first and second electrodes 120and 130 on the substrate 101, a nano capsule liquid crystal layer 140 onthe first and second electrodes 120 and 130, and first and secondpolarizing plates 150 and 160 that are below the substrate 101 anddirectly on the nano capsule liquid crystal layer 140, respectively.

The nano capsule liquid crystal layer 140 is formed with nano capsules142 that are dispersed in a buffer layer 143. Each nano capsule 142 mayhave a size less than wavelength of a visible light, e.g., no more than320 nm, and is filled with liquid crystal molecules 141 randomlyaligned. The nano capsule liquid crystal layer 140 including the nanocapsules 142, the liquid crystal molecules 141 within the nano capsules142, and the buffer layer 143 may be formed using a variety of formationmethods, such as a printing method, a coating method, or a droppingmethod. The nano capsule liquid crystal layer 140 may be formed in afilm type over the first and second electrodes 120 and 130. Accordingly,unlike the related art LCD using two substrates, the LCD 100 of thisembodiment can be manufactured with one substrate 101, and thus the LCDof light weight and thin profile can be achieved, and production costcan be reduced.

Further, the nano capsule liquid crystal layer 140 does not have theproblem of the related art that the gap between the related art twosubstrates becomes non-uniform or changes by an external pressure orimpact. Thus, when forming the substrate 101 using a flexible materialsuch as a plastic, the nano capsule liquid crystal layer 140 can beeffectively applied to a flexible LCD.

Further, the nano capsule liquid crystal layer 140 has an opticalisotropy when an electric field is not applied. However, the nanocapsule liquid crystal layer 140 has an optical property that when anelectric field is applied, the liquid crystal molecules 141 in the nanocapsule 142 are aligned in a direction of the electric field andbirefringence of a light incident on the nano capsule liquid crystallayer 140 is produced. Accordingly, the nano capsule liquid crystallayer 140 can form an optical axis according to an applied electricfield, and by controlling an optical property using this, a light can betransmitted.

Further, the first polarizing plate 150 produces a polarization of alight to be incident on the nano capsule liquid crystal layer 140 fromthe backlight 170. The second polarizing plate 160 blocks a light thatis incident on the nano capsule liquid crystal layer 140 and then passesthrough the nano capsule liquid crystal layer 140 without polarizationby a birefringence effect of the nano capsule liquid crystal layer 140.

A polarization axis of the first polarizing plate 150 and a polarizationaxis of the second polarizing plate 160 are perpendicular to each other.For example, if the polarization axis of the first polarizing plate 150has a 0 or 90 degree angle, the polarization axis of the secondpolarization plate 160 has a 90 or 0 degree angle.

A principle of operating the LCD 100 including the nano capsule liquidcrystal layer 140 is explained below. First, when an electric field isnot induced between the first and second electrodes 120 and 130, thenano capsule liquid crystal layer 140 passes through a light entering itthrough the first polarizing plate 150, and thus the LCD 100 displays ablack state.

In other words, in the off state with no electric field being applied, alight entering the first polarizing plate 150 from the backlight 170 isselectively transmitted at a specific angle while passing through thefirst polarization plate 150, then the light entering the nano capsuleliquid crystal layer 140 is transmitted through the nano capsule liquidcrystal layer 140 with a minimal scattering phenomenon and then reachesthe second polarizing plate 160. Finally, a light passing through thefirst polarization plate 150 having a polarization axis of, for example,a 0 degree angle enters the second polarization plate 160 having thepolarization axis of, for example, a 90 degree angle, thus this light isblocked by the second polarizing plate 160 perpendicular in polarizingaxis to the first polarizing plate 150, and thus the LCD 100 displaysthe black state.

As described above, unlike the related art LCD requiring that a pair ofalignment layers are arranged on a pair of substrates opposing to eachother, respectively, and a liquid crystal is injected between thesubstrates and is aligned to have predetermined pitch and direction, theLCD 100 of this embodiment can display the black state using the opticalproperty of the nano capsule liquid crystal layer 140 and thus does notrequire an additional process of aligning a liquid crystal. Accordingly,the LCD 100 of this embodiment can eliminate processes of printing andrubbing an alignment layer that the related art LCD necessarilyrequires. In this embodiment, the nano capsule liquid crystal layer 140may contact the first and second electrodes 120 and 130 without analignment layer therebetween, and may contact the second polarizationplate 160 without an alignment layer therebetween.

When an electric field is induced between the first and secondelectrodes 120 and 130, the nano capsule liquid crystal layer 140rotates a polarization axis of a light entering the nano capsule liquidcrystal layer 140 through the first polarization plate 150 by a 90degree angle, and thus the LCD 100 displays a white state. In detail, inthe on state with the electric field being induced, since the liquidcrystal molecules 141 in the nano capsule 142 are arranged in parallelwith a direction of the electric field, a birefringence effect by thealignment of the liquid crystal molecules 141 is produced.

In this case, a light entering the nano capsule liquid crystal layer 140through the first polarizing plate 150 changes in polarization by thebirefringence effect of the nano capsule liquid crystal layer 140. Whena retardation, Δn*d, of the nano capsule liquid crystal layer 140 meetsa λ/2 condition of a light incident thereon, a polarization axis of theincident light is rotated by 90 degree angle, thus this light is notabsorbed by the second polarizing plate 160 perpendicular inpolarization axis to the first polarizing plate 150 and passes throughthe second polarizing plate 160, and thus the LCD 100 displays the whitestate.

Since the LCD 100 including the nano capsule liquid crystal layer 140controls a light transmission amount through a refractive index of thenano capsule liquid crystal layer 140, liquid crystal molecules havingtwo or three times the refractive index of the liquid crystal moleculesof the related art is required. However, since a liquid crystal moleculehaving a greater refractive index has a greater wavelength dispersionproperty, a problem may occur that a color coordinate goes awry (e.g.,becomes non-uniform) when displaying images and thus a white balance isnot achieved.

Further, according to a Kerr effect, an LCD has a property that arefractive index inducement of a short wavelength is produced more thanthat of a long wavelength when operating the LCD in the same operationcondition (electrode, voltage and the like), and because of thisproperty, an efficiency of a blue region is greater than that of a redregion. Accordingly, a color coordinate is biased to a blue side, andthus a problem may happen that a bluish image is displayed. Features ofthis embodiment to resolve the above problems are explained below.

FIG. 3 is a view illustrating unit pixels of an LCD according to theembodiment of the present invention. Referring to FIG. 3, a unit pixel200 includes first to third sub-pixels SP1 to SP3 arranged in a delta(Δ) structure. The first to third sub-pixels SP1 to SP3 may display red,green and blue, respectively, and these sub-pixels SP1 to SP3 constituteone unit pixel 200.

FIGS. 4A and 4B are views illustrating electrode arrangement structuresof sub-pixels of a unit pixel of FIG. 3. First, referring to FIGS. 4Aand 4B, the LCD of this embodiment includes a substrate 101 including aunit pixel 200, of a delta (Δ) structure, having first to thirdsub-pixels SP1 to SP3, and first and second electrodes 120 and 130arranged in each of the first to third sub-pixels SP1 to SP3.

In detail, the first electrode 120 includes a first bar 120 a and aplurality of second bars 120 b branching off from the first bar 120 aforming a fork-like pattern, and the second electrode 130 includes afirst bar 130 a and a plurality of second bars 130 b branching off fromthe first bar 130 a forming a fork-like pattern. Further, the first bar120 a of the first electrode 120 faces and is parallel with the firstbar 130 a of the second electrode 130, and the second bars 120 b of thefirst electrode 120 are interleaved with the second bars 130 b of thesecond electrode 130 (e.g., the second bars 120 b and 130 b mayalternate).

Electric fields between the first and second bars 120 a and 120 b of thefirst electrode 120 and the first and second bars 130 a and 130 b of thesecond electrode 130 are produced at the shortest distances between thefirst and second bars 120 a and 120 b of the first electrode 120 and thefirst and second bars 130 a and 130 b of the second electrode 130, andwhen an electric field distribution aligns with a first polarizationaxis P1 or a second polarization axis P2 perpendicular to the firstpolarization axis P1, a light transmittance is minimized.

Accordingly, in the LCD 100 of this embodiment, the first bars 120 a and130 a , and the second bars 120 b and 130 b of the third sub-pixel SP3make a first angel θ1, and a second angle θ2, respectively, relative tothe first polarization axis P1, thus distributions of electric fieldsbetween the first and second bars 120 a and 120 b of the first electrode120 and the first and second bars 130 a and 130 b of the secondelectrode 130 maximally un-aligns with the first and second polarizationaxes P1 and P2, and thus a light transmittance can be maximized.

Further, the first angle θ1 and the second angle θ2 may be the same inabsolute value, and in order that distributions of electric fieldsbetween the first and second bars 120 a and 120 b of the first electrode120 and the first and second bars 130 a and 130 b of the secondelectrode 130 maximally disaccord with the first and second polarizationaxes P1 and P2, each of the first angle θ1 and the second angle θ2 maybe a 45 degree angle. Further, the first bars 120 a and 130 a of thefirst and second sub-pixels SP1 and SP2 are arranged parallel with thefirst polarization axis P 1.

Further, referring to FIG. 4A, the second bars 120 b and 130 b of thefirst sub-pixel SP1 are parallel with the first bars 120 a and 130 a ofthe third sub-pixel SP3, and the second bars 120 b and 130 b of thesecond sub-pixel SP2 are parallel with the second bars 120 b and 130 bof the third sub-pixel SP3. Alternatively, referring to FIG. 4B, thesecond bars 120 b and 130 b of the first sub-pixel SP1 are parallel withthe second bars 120 b and 130 b of the third sub-pixel SP3, and thesecond bars 120 b and 130 b of the second sub-pixel SP2 are parallelwith the first bars 120 a and 130 a of the third sub-pixel SP3.

In this case, distributions of electric fields between the second bars120 b of the first electrode 120 and the second bars 130 b of the secondelectrode 130, in the first and second sub-pixels SP1 and SP2, maximallyun-aligns with the first and second polarization axes P1 and P2, andthus a light transmittance is maximized. However, distributions ofelectric field between the first bar 120 a of the first electrode 120and the second bars 130 b of the second electrode 130, and between thefirst bar 130 a of the second electrode 130 and the second bars 120 b ofthe first electrode 120 align with the first or second polarization axisP1 or P2, and thus a transmittance is minimized.

Accordingly, even though the LCD of this embodiment uses liquid crystalmolecules having two or three times the refractive index of the relatedart liquid crystal molecules, by arranging a color filter requiring arelatively greater light transmittance at the third sub-pixel SP3 thathas a light transmittance greater than the first and second sub-pixelsSP1 and SP2, and arranging a color filter requiring a relatively lesslight transmittance at the first or second sub-pixel SP1 or SP2, a colorcoordinate becomes uniform when displaying images and thus a whitebalance can be achieved.

Particularly, by placing a blue color filter at the first or secondsub-pixel SP1 or SP2 and placing a red or green color filter at thethird sub-pixel SP3, a color coordinate that is biased to a blue sideand display of a bluish image can be prevented. To obtain the aboveadvantage, in the related art, by forming sub-pixels that are differentin an electrode interval and an area, light transmittance is adjusted.However, forming sub-pixels in this manner may produce a display defectdue to light diffraction. Thus, in this embodiment, along theabove-described advantage, by forming the first to third sub-pixels SP1to SP3 having the same area and the same distance between the secondbars 120 b and 130 b , a display defect due to light diffraction can beprevented.

FIG. 5 is a view illustrating a pixel arrangement produced with aplurality of unit pixels according to the embodiment of the presentinvention. When the first and second electrodes 120 and 130 are arrangedas above, the first and second sub-pixels SP1 and SP2 each have aparallelogram shape, the third sub-pixel SP3 has a rhombus shape, andthe unit pixel 200 consisting of the first to third sub-pixels SP1 toSP3 has a hexagon shape.

Further, referring to FIG. 5, the first to third sub-pixels SP1 to SP3of the delta (Δ) structure may display green (G), blue (B) and red (R),respectively, and these sub-pixels SP1 to SP3 constitute one unit pixel200. In this case, among the plurality of unit pixels 200, twoneighboring unit pixels 200 share the third sub-pixel SP3, and thus morenatural image can be displayed.

FIG. 6 is a view schematically illustrating the second sub-pixel ofFIGS. 4A and 4B. Since the first to third sub-pixels SP1 to SP3 have thesame components and the same relationship between the same components,the second sub-pixel SP2 are representatively explained. Referring toFIG. 6, the LCD 100 of this embodiment includes a gate line GL on asubstrate 101, first and second data lines DL1 and DL2 crossing the gateline GL to define the second sub-pixel SP2, first and second electrodes120 and 130 located in the second sub-pixel SP2, and first and secondthin film transistors Tr1 and Tr2.

In detail, the first electrode 120 includes a first bar 120 a and aplurality of second bars 120 b branching off from the first bar 120 aforming a fork-like pattern, and the second electrode 130 includes afirst bar 130 a and a plurality of second bars 130 b branching off fromthe first bar 130 a forming a fork-like pattern. Further, the first bar120 a of the first electrode 120 faces and is parallel with the firstbar 130 a of the second electrode 130, and the second bars 120 b of thefirst electrode 120 are interleaved with the second bars 130 b of thesecond electrode 130 (e.g., the second bars 120 b and 130 b mayalternate).

Further, the first thin film transistor Tr1 is connected to the gateline GL and the first data line DL1 and supplies a first data voltage tothe first electrode 120. The second thin film transistor Tr2 isconnected to the gate line GL and the second data line DL2 and suppliesa second data voltage, which has a level opposite to a level of thefirst data voltage, to the second electrode 130.

The first thin film transistor Trl includes a gate electrode G connectedto the gate line GL, a source electrode S connected to the first dataline DL1, and a drain electrode D connected to the first electrode 120.The second thin film transistor Tr2 includes a gate electrode Gconnected to the gate line GL, a source electrode S connected to thesecond data line DL2, and a drain electrode D connected to the secondelectrode 130.

A method of driving the LCD is explained with reference to FIG. 6.

First, in the related art LCD, only a data voltage supplied from a dataline to a first electrode is alternated or varied between voltages. Inother words, with respect to a constant common voltage supplied from acommon line, as a reference, a data voltage supplied from a data line toa first electrode alternates between positive and negative voltages.

However, in the LCD 100 of this embodiment, both the first and seconddata voltages supplied from the first and second data lines DL1 and DL2to the first and second electrodes 120 and 130, respectively, alternateor vary between positive and negative voltages. In other words, thefirst data voltage is supplied from the first data line DL1 to the firstelectrode 120 alternating between positive and negative voltages withrespect to a constant common voltage, and the second data voltage havinga level opposite to the level of the first data voltage is supplied fromthe second data line DL2 to the second electrode 130. Thus, since theLCD 100 of this embodiment applies two times the data voltage of therelated art LCD to each of the sub-pixels SP1 to SP3, a lighttransmittance of the nano capsule liquid crystal layer (140 of FIG. 2)can be improved.

FIG. 7 is a graph illustrating a relative light transmittance to arelative voltage applied to each sub-pixel of the embodiment of thepresent invention. FIG. 8 is a view illustrating brightness by area ofeach sub-pixel according to the embodiment of the present invention.

Referring to FIG. 7, as a relative voltage increases, a lighttransmittance of the third sub-pixel SP3 is greater than those of thefirst and second sub-pixels SP1 and SP2. Accordingly, referring to FIG.8, a dark state of the third sub-pixel SP3 is minimized compared withthe first and second sub-pixels SP1 and SP2.

In detail, regarding the dark state between the first bar 120 a of thefirst electrode 120 and the second bar 130 b of the second electrode 130and between the first bar 130 a of the second electrode 130 and thesecond bar 120 b of the first electrode, the first and second sub-pixelsSP1 and SP2 are greater than the third sub-pixel SP3. This means thatthe third sub-pixel SP3 has a light transmittance greater than the firstand second sub-pixels SP1 and SP2.

In the above-described embodiment, a uniform color coordinate whendisplaying images and a white balance can be achieved, and particularly,it a color coordinate that is biased to a blue side and display of abluish image can be prevented.

Further, processes of printing and rubbing an alignment layer requiredin the related art can be eliminated, and the LCD can be manufacturedwith one substrate. Thus, an LCD of thin profile and light weight can beachieved and production cost can be reduced.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in a display device of thepresent invention without departing from the sprit or scope of thedisclosure. Thus, it is intended that the present invention covers themodifications and variations of this disclosure provided they comewithin the scope of the appended claims and their equivalents.

The present invention encompasses various modifications to each of theexamples and embodiments discussed herein. According to the invention,one or more features described above in one embodiment or example can beequally applied to another embodiment or example described above. Thefeatures of one or more embodiments or examples described above can becombined into each of the embodiments or examples described above. Anyfull or partial combination of one or more embodiment or examples of theinvention is also part of the invention.

What is claimed is:
 1. A liquid crystal display device, comprising: asubstrate including a unit pixel having first to third sub-pixelsarranged in a delta structure; and a first electrode and a secondelectrode in each of the first to third sub-pixels, each of the firstand second electrodes including a first bar and a plurality of secondbars branching off from the first bar, the first bar of the firstelectrode and the first bar of the second electrode facing each otherand being parallel with each other, the second bars of the firstelectrode and the second bars of the second electrode interleaved witheach other, wherein the first and second bars of the third sub-pixelmakes first and second angles, respectively, relative to a firstpolarization axis.
 2. The liquid crystal display device of claim 1,wherein the first bar of each of the first and second sub-pixels isparallel with the first polarization axis, wherein the second bar of thefirst sub-pixel is parallel with the first or second bar of the thirdsub-pixel, and wherein the second bar of the second sub-pixel isparallel with the second or first bar of the third sub-pixel.
 3. Theliquid crystal display device of claim 2, wherein the first and secondangles are the same in absolute value.
 4. The liquid crystal displaydevice of claim 3, wherein the first and second angles are 45 degreeangles relative to the first polarization axis.
 5. The liquid crystaldisplay device of claim 3, wherein each of the first and secondsub-pixels has a parallelogram shape, the third sub-pixel has a rhombusshape, and the unit pixel has a hexagon shape.
 6. The liquid crystaldisplay device of claim 5, wherein the first to third sub-pixels havethe same area and have the same distance between the correspondingsecond bars of the first to third sub-pixels.
 7. The liquid crystaldisplay device of claim 2, further comprising first and second thin filmtransistors connected to the first and second electrodes, respectively.8. The liquid crystal display device of claim 2, further comprising: anano capsule liquid crystal layer that is on and contacts the first andsecond electrodes; a first polarizing plate below the substrate andhaving the first polarization axis; and a second polarizing plate thatis on and contacts the nano capsule liquid crystal layer, and has asecond polarization axis perpendicular to the first polarization axis.9. The liquid crystal display device of claim 8, wherein the nanocapsule liquid crystal layer is configured in a film type.
 10. Theliquid crystal display device of claim 8, wherein the nano capsuleliquid crystal layer includes a plurality of nano capsules that aredispersed in a buffer layer.
 11. The liquid crystal display device ofclaim 10, wherein a nano capsule of the plurality of nano capsules has asize less than wavelengths of a visible light and is filled with liquidcrystal molecules randomly aligned.
 12. The liquid crystal displaydevice of claim 1, wherein at least one of the first and secondsub-pixels includes a blue color filter, and the third sub-pixelincludes a red or green color filter.
 13. The liquid crystal device ofclaim 1, further comprising: a first data line and a second data linefor the first to third sub-pixels, the first data line supplying a firstdata voltage to a respective first electrode, the second data linesupplying a second data voltage to a respective second electrode,wherein the second data voltage has a level opposite to a level of thefirst data voltage.
 14. A liquid crystal display device, comprising: asubstrate including a unit pixel of a delta structure including first tothird sub-pixels; a first electrode and a second electrode formed on thesubstrate in each of the first to third sub-pixels; a nano capsuleliquid crystal layer on the first and second electrodes; and a firstpolarizing plate below the substrate and a second polarizing platedirectly on the nano capsule liquid crystal layer, wherein the unitpixel has a hexagon shape.
 15. The liquid crystal display device ofclaim 14, wherein each of the first and second electrodes includes afirst bar and a plurality of second bars branching off from the firstbar, the first bar of the first electrode and the first bar of thesecond electrode facing each other and being parallel with each other,the second bars of the first electrode and the second bars of the secondelectrode interleaved with each other, and wherein the first and secondbars of the third sub-pixel make first and second angles, respectively,relative to a first polarization axis.
 16. The liquid crystal displaydevice of claim 15, further comprising: a first data line and a seconddata line for the first to third sub-pixels, the first data linesupplying a first data voltage to a respective first electrode, thesecond data line supplying a second data voltage to a respective secondelectrode, wherein the second data voltage has a level opposite to alevel of the first data voltage.
 17. The liquid crystal display deviceof claim 14, wherein at least one of the first and second sub-pixelsincludes a blue color filter, and the third sub-pixel includes a red orgreen color filter.
 18. The liquid crystal display device of claim 14,wherein the nano capsule liquid crystal layer is configured in a filmtype.
 19. The liquid crystal display device of claim 14, wherein thenano capsule liquid crystal layer includes a plurality of nano capsulesthat are dispersed in a buffer layer.
 20. The liquid crystal displaydevice of claim 19, wherein a nano capsule of the plurality of nanocapsules has a size less than wavelengths of a visible light and isfilled with liquid crystal molecules randomly aligned.